(172) 
marginate (‘propter excipuli defectum immarginata,’ Koerb.) and this is 
possibly not far from expressing the now common opinion of lichenists. 
But the presumption is against such anomaly ; and both Acharius (Lich- 
enogr.) aud Fries have described a proper exciple, coloured like the disk 
in its normal (black) state. Very few however, it is likely, have been 
able to repeat these observations, and I offer therefore the following, for 
what they shall prove to be worth. In their common, convex condition, 
the (mature) apothecia illustrate certainly Acharius’s description of an 
immarginate, turgid disk, which has taken up with it in its turgescence, 
a portion (apophysis, Ach.) of the thallus upon which it grows; and 
there is little in this case, even in section, to suggest an excipular margin. 
But flatter, which are also to be considered more normal examples, are often 
a little elevated, at all points, above the thallus, when there appears (quite 
frequently in our plant, but to be observed also in the European) a white, 
depressed, marginal ring, contrasting with the colour of the epithallus, and, 
in some of the specimens published by the writer (Lich. ers. n. 137) visible 
to the naked eye. Examined with a sufficient lens this ring is seen to be 
minutely filamentous, and comparable therefore (it is possible) with the 
filamentous border of Biatora tricholoma, Mont.; and similarly also to 
Montagne’s lichen, as described by him, in which this border is said to be 
rufous (as it occurs in a Cuban specimen before me, referable here) the 
corresponding part in the northern plant is not rarely more or less tinged 
with the hue of the red layer, commonly taken for hypothecial (‘ exc/puli 
proprii sanguinci, Mass.). But the filamentous margin of the tropical 
Biatora becomes finally all but obsolete, and a proper, excipular border 
obscurely visible; and, in like manner, in the oldest and largest, flat apo- 
thecia (measuring now, in undoubtedly single instances, from 2 to 3™™- in 
width) of the set of North American specimens of H. sanguinarium 
before me, the filamentous ring ceases to be observable, and there appears 
instead, not seldom, what in other lichens might easily be construed as a 
depressed, originally pale but blackening (or now, here and there redden- 
ing) proper margin. And whether the comparison have any real value or 
not, there is little in the appearance of this supposed, or simulated mar- 
gin to distinguish it from the equally depressed and blackening, true 
border in old, turgid apothecia of H. endochroma (Fée) Flot. (Wright 
Lich. Cub. n. 226); and the whole habit of such apothecia, both in the 
cited species, and in H. leptocheilum, Tuck. (Lich. Cub. n. 227) is not a 
little suggestive of the northern lichen; though young fruits offer noth- 
ing certainly of the strange convexity of those of the latter. But in 
Biatora quernea, another lichen of the present family which has been 
repeatedly described as structurally immarginate, the proper margin (as 
noted in Obs. Lich. 1. ¢. p. 275) though not undiscoverable in young apo- 
thecia, becomes yet clearly evident only in the largest and most perfect 
ones. The protoplasm of the large spore of H. sanguinarium acquires 
the same yellowish tinge which is observable in those of H. versicolor 
